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Wilson, P.A., Lyle, M., and Firth, J.V. (Eds.) Proceedings of the Ocean Drilling Program, Scientific Results Volume 199

18. DATA REPORT: HIGH-RESOLUTION STABLE ISOTOPE RECORDS ACROSS THE PALEOCENE/EOCENE BOUNDARY, ODP SITES 1220 AND 12211 Flavia Nunes2 and Richard D. Norris2

ABSTRACT High-resolution carbon and oxygen isotope records were produced from 240 analyses of two species of benthic foraminifers and bulk carbonate in sediments from across the Paleocene/Eocene (P/E) boundary in Ocean Drilling Program (ODP) Holes 1220B and 1221C. Although part of the carbon isotope excursion is not recorded in either Hole 1220B or Hole 1221C because of carbonate dissolution, both sites do record a significant part of the main geochemical excursion. The benthic foraminifers from Hole 1220B are believed to provide reliable geochemical records of the magnitude of the P/E excursion as judged by the quality of foraminifer preservation and similarity of the carbon isotope record to that seen at other deep-sea sites. However, anomalously positive values in the benthic δ18O record in sediments from Hole 1221C and bulk carbonate in sediments from Hole 1220B indicate that diagenesis masks the primary isotopic signature in this part of the records. The Paleocene–Eocene Thermal Maximum is only observed in the Hole 1220B benthic foraminifer records, with a δ18O excursion of –0.65‰ to –0.85‰. The magnitude of the carbon isotope excursion is as much as 0.96‰ in Hole 1221C and 2.01‰ in Hole 1220B. Although smaller than at Southern Ocean Site 690 (2.6‰), the carbon isotope excursion in Hole 1220B is of similar magnitude to that observed in Deep Sea Drilling Project and ODP Sites 527, 738, and 1051 and the Alamedilla Section in Spain (–2.1‰, –1.6‰, –1.9‰, and –1.7‰, respectively).

1 Nunes, F., and Norris, R.D., 2005. Data report: High-resolution stable isotope records across the Paleocene/ Eocene boundary, ODP Sites 1220 and 1221. In Wilson, P.A., Lyle, M., and Firth, J.V. (Eds.), Proc. ODP, Sci. Results, 199, 1–12 [CD-ROM]. Available from: Ocean Drilling Program, Texas A&M University, College Station TX 778459547, USA. 2 Scripps Institution of Oceanography, 9500 Gilman Drive, MC 0208, La Jolla CA 92092, USA. Correspondence author: [email protected]

Initial receipt: 30 March 2004 Acceptance: 31 January 2005 Web publication: 15 December 2005 Ms 199SR-206

F. NUNES AND R.D. NORRIS DATA REPORT: HIGH-RESOLUTION STABLE ISOTOPE RECORDS

INTRODUCTION One of the goals of Ocean Drilling Program (ODP) Leg 199 was to study the changes in ocean circulation in the Pacific Basin during the Paleogene. Stable isotopes are useful proxies for this purpose because the temperature of water masses can be deduced from δ18O records, whereas δ13C can be used as a nutrient tracer for ocean circulation. We present oxygen and carbon isotope values from bulk carbonate and benthic foraminifers across the Paleocene/Eocene (P/E) boundary in Holes 1220B and 1221C in the equatorial Pacific Ocean. The P/E boundary is characterized by an abrupt negative excursion in both oxygen and carbon isotopes, which is an indication of transient changes in temperature and the global carbon cycle at this time. Here, high-resolution sampling (3–5 k.y. in the core of the carbon isotope excursion) focused on the P/E transition to capture a detailed record of the carbon and oxygen isotope excursions in the deep equatorial Pacific. Both sites are assumed to have had a paleodepth of ~2500–2600 m at the time of the P/E boundary. It is important to recognize that there may be significant uncertainty in the actual paleodepth for both sites, which is estimated by assuming that both sites were deposited near the crest of the newly formed oceanic ridge. Both sites were drilled on 56Ma crust (considered to have formed near 2500 m water depth) but then had perhaps 500,000 to 1 million years to subside before deposition of the P/E sequence. Hence, it is possible that the sites actually reached depths of ~2580–2660 m prior to deposition of the P/E section, depending upon what age is assumed for the P/E boundary and assuming constant thermotectonic subsidence of the ocean crust. In addition, bottom roughness around the sites could account for perhaps up to an additional ±100 m of depth uncertainty. We assume an age for the P/E boundary of ~55.2 Ma, suggesting that the sites may both have reached depths of as much as ~2660–2760 m by the time the carbonate sequence began to accumulate.

METHODS AND MATERIALS Bulk Carbonate Sediment samples from Holes 1220B and 1221C were taken at 5-cm intervals and were allowed to dry overnight in a Memmert Wisconsin oven at 50°C. The samples were homogenized by grinding with a mortar and pestle and were weighed on a Mettler Toledo MX5 microbalance with a precision of ~1 µg. Sample size varied depending on the carbonate content of the interval, published in the Leg 199 Initial Reports volume (Lyle, Wilson, Janecek, et al., 2002). About 500 µg of sediment was analyzed in samples with high carbonate content, whereas ~1000 µg of sediment was analyzed in samples with low CaCO3 content. Carbon and oxygen isotopic composition of these sediments were measured at Scripps Institution of Oceanography (SIO; USA) using an automated common acid bath carbonate preparation device (Fairbanks device) attached to a Finnigan MAT252 mass spectrometer. NBS-19 was used as a standard, with 7 standard analyses per run of 40 unknowns. The average instrument error is 250-µm fraction for isotopic analyses. Approximately 10–15 individuals of each genus or species were selected so that an average signature for the interval was obtained. Carbon and oxygen isotopic composition of these benthic foraminifers were measured at SIO with the same methodology reported for bulk carbonate.

Preservation of Materials The P/E boundary interval in both Holes 1220B and 1221C consists of a series of colorful beds in what is otherwise a foraminifer-nannofossil ooze. The boundary is identified partly by the last appearance of Paleocene benthic foraminifers at 199.68 meters below seafloor (mbsf) in Hole 1220B and at 154.31 mbsf in Hole 1221C. In addition, the P/E boundary in Hole 1220B is marked by the occurrence of the “excursion fauna” of planktonic foraminifers (Lyle, Wilson, Janecek, et al., 2002). In both holes, the boundary beds change upsection from yellow dolomite-rich sediments to rose-pink, black, dark brown, and, eventually, tan calcareous ooze in the interval spanned by the most negative benthic foraminifer δ13C ratios. These multicolored beds, representing the core of the P/E boundary interval, have low carbonate content. The coarse (>38 µm) fraction in samples from Holes 1220B and 1221C are dominated by benthic foraminifers because of the dissolution of most planktonic forms. Planktonic foraminifers are sparse but occur throughout most of the section in Hole 1220B, whereas Hole 1221C is nearly devoid of them. Benthic foraminifers are abundant at both sites except within a carbonate dissolution horizon occurring between 199.40 and 199.70 mbsf in Hole 1220B and between 154.10 and 154.30 mbsf in Hole 1221C. Foraminifers are generally well preserved in Hole 1220B, particularly within and above the PETM, but typically display a coarse, sugary coating in Hole 1221C. Below the carbonate dissolution horizon, benthic foraminifers in both holes commonly have a sugary surface texture, and both planktonic and benthic foraminifers in Hole 1220B are occasionally overgrown by glassy, yellow dolomite rhombs. In some intervals of both sites, particularly below the P/E boundary, dolomite rhombs compose a significant portion of the fine fraction. Benthic foraminifers containing dolomite rhombs on their surface were not selected for isotope analysis. Carbonate preservation is distinctly worse in Hole 1221C than it is in Hole 1220B. The different quality of preservation between the sites may reflect a slightly deeper paleodepth for Hole 1221C than Hole 1220B because we expect that differences in the actual age of the seafloor beneath these sites and bottom roughness might account for differences as great as several hundred meters in their actual paleodepths. The two

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sites also differ in paleolatitude, with the area around Hole 1220 having crossed the equator about the time of the P/E boundary, whereas Hole 1221C was nearly 200 km to the north (Lyle, Wilson, Janecek, et al., 2002). Hence, Hole 1221C may have been farther from the belt of equatorial carbonate accumulation at the P/E boundary and in an area with a shallower carbonate compensation depth than Hole 1220B.

PROVISIONAL TIMESCALE

F1. Carbon and oxygen isotope data, Hole 1220B, p. 8. -0.5

0.5

2.5 -1.5

1.5

-0.5

0.5

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2.5

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198.00 Nuttalides truempyi Cibicidoides spp. Bulk CaCO3

Depth (mbsf)

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199.00

199.50

200.00

F2. Carbon and oxygen isotope data, Hole 1221C, p. 9. δ13C (‰) 0.0 152.00

0.5

1.0

δ18O (‰)

1.5

2.0

2.5 -2.0

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Nuttalides truempyi Cibicidoides spp. Bulk CaCO3 152.50

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T1. Stable isotope data, Sites 1220 and 1221, p. 11

F3. Carbon and oxygen isotope data, Sites 1220 and 1221, p. 10. δ13C (‰) -1.5 54.5

-1.0

54.6 1220-nutt 1220-cib 1221-nutt 1221-cib

54.7

RESULTS

54.8

Age (Ma)

The δ13C and δ18O data from Holes 1220B and 1221C obtained from bulk carbonate and benthic foraminifers are shown in Table T1 and in Figures F1 and F2.

δ18O (‰)

δ13C (‰) -1.5 197.50

Depth (mbsf)

A provisional timescale based on the astrochronology of the P/E boundary at ODP Hole 690 (Röhl et al., 2000) was developed for sediments from Holes 1220B and 1221C. Three common points, recognizable on the δ13C curves from Site 690, and Holes 1220B and 1221C were chosen for correlation. These points are the onset of the excursion at 55.234 Ma, the minimum δ13C value at 55.1815 Ma, and the inflection point where carbon isotope ratios recover from the excursion at 55.0011 Ma. The locations of the datum points are indicated on Figures F1 and F2. A timescale for Holes 1220B and 1221C was created by interpolation between these three datum points and can be found in Table T1 and in Figure F3. Sedimentation rates were assumed to be constant above the highest datum point and below the lowest datum point. The accuracy of this timescale depends on appropriate selection of datum points. Gaps in the isotope record of ~30 cm in Hole 1220B and of ~20 cm in Hole 1221C restrict our ability to identify the exact onset of the carbon isotope excursion. The start of the carbon isotope excursion is unlikely to have been incorrectly located by more than the duration of these gaps. We have assumed that carbonate burndown during the PETM is minimal because errors as large as these would require extensive dissolution of seafloor sediments deposited before the start of the carbon isotope excursion. Nonetheless, it is possible that the isotope record from Sites 1220 and 1221 does not capture the most negative value of the δ13C excursion either due to dissolution or a hiatus. Despite this potential source of error, we believe the minimum δ13C value is a reasonable datum point because it is more readily identified in each of the records, whereas attempting to correlate a different point in the isotope curve, particularly a point where the curve changes rapidly, is likely to be more ambiguous. Although the use of biostratigraphic datums would strengthen the accuracy of this timescale, there are intervals in the sedimentary record where this information is not available because the calcareous material is absent. At the moment, there is no well-defined set of biostratigraphic events that can be used to subdivide the interval within the P/E carbon isotope excursion, and cyclostratigraphies have been constructed for only a few sites. For this reason we believe the approach used here provides a good chronological estimate for these two sites. At the very least, we think that our chronology allows us to accurately compare parts of the isotope record that fall before, during, and after the PETM.

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δ18O (‰) 0.5

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F. NUNES AND R.D. NORRIS DATA REPORT: HIGH-RESOLUTION STABLE ISOTOPE RECORDS The carbon isotope excursion is present at both sites and appears on all δ13C records. The magnitude of the excursion in Hole 1220B is 2.01‰ in the N. truempyi record, 1.35‰ in the Cibicidoides spp. record, and 1.44‰ in the bulk carbonate record. In Hole 1221C, the magnitude of the carbon isotope excursion is 0.96‰, 0.83‰, and 0.82‰ for N. truempyi, Cibicidoides spp., and bulk carbonate, respectively. The δ13C records from Hole 1220B are larger in magnitude than those produced from Hole 1221C. The δ13C values from Leg 199 sites are lower than the magnitude observed at higher latitudes, such as the 2.6‰ excursion seen in N. truempyi at Site 690 in the Weddell Sea (Kennett and Stott, 1991) but is of similar magnitude to those observed in Deep Sea Drilling Project and ODP Sites 527, 738, and 1051 and the Alamedilla Section in Spain (–2.1‰, –1.6‰, –1.9‰, and –1.7‰, respectively) (Katz et al., 1999; Lu et al., 1998; Lu and Keller, 1993; Thomas and Shackleton, 1996). All of these sites (including ODP 690) contain small gaps in the δ13C record like the Leg 199 sites because of some combination of carbonate dissolution or absence of appropriate foraminifers for isotopic analysis. There appears to be a systematic offset between the δ13C records of bulk carbonate, N. truempyi, and Cibicidoides spp. in both Holes 1220B and 1221C. The Cibicidoides spp. record consistently has the lightest values of δ13C, whereas the bulk carbonate record consistently has the heaviest δ13C values of both sites. The average offset between Cibicidoides spp. and N. truempyi is 0.21 ± 0.29‰ (N = 86); between Cibicidoides spp. and the bulk carbonate record, the offset is 1.10 ± 0.38‰ (N = 56); and the offset between the N. truempyi record and the bulk carbonate record is 0.86 ± 0.31‰ (N = 52). Our results differ from those of Katz et al. (2003), who report that δ13C of Cibicidoides spp. is typically more positive than that of N. truempyi. We can only note that the interspecies offset in our results is internally consistent and is based upon well-preserved foraminifers in Hole 1220B that are selected with a narrowly defined species concept even if we have not identified the species of Cibicidoides used in our analysis. Unfortunately, Cibicidoides spp. is known to contain a large number of species that are likely to have distinctly different isotope fractionation effects, and these may account for the contrast between our results and those of Katz et al. (2003). The PETM is recognized only in the benthic foraminiferal δ18O records from Hole 1220B, where an excursion of –0.65‰ is observed in the N. truempyi record and –0.86‰ is observed in the Cibicidoides spp. record. In contrast, the bulk carbonate δ18O values at this site actually increase across the P/E boundary to unusually heavy values of δ18O, reaching up to +4.0‰. It is unlikely that these ratios represent actual deep-sea δ18O values in a time when the world’s oceans experienced a ubiquitous increase in temperature. These anomalous values are coincident with the carbonate dissolution horizon, where dolomite crystals are abundant. It is likely that the δ18O values in this part of the bulk carbonate record are of diagenetic origin, rather than a primary signal. Bulk carbonate δ13C in Hole 1220B also yields unusually positive ratios, suggesting that carbon isotopes have also been affected by diagenesis. In Hole 1221C, neither the bulk carbonate record of δ18O nor the benthic foraminiferal δ18O records have a negative excursion related to the PETM. The data from the bulk carbonate record have much scatter and do not show a clear pattern, whereas the benthic foraminifer records show an inverse pattern from that expected: δ18O values in-

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F. NUNES AND R.D. NORRIS DATA REPORT: HIGH-RESOLUTION STABLE ISOTOPE RECORDS crease across the P/E boundary. We also attribute this unusual result to diagenesis.

SUMMARY Stable isotope records based on analyses of the benthic foraminifers N. truempyi and Cibicidoides spp., as well as bulk carbonate records spanning the P/E boundary, have been produced at a high-resolution interval. The magnitude of the δ13C excursion is much smaller in Hole 1221C when compared to Hole 1220B, a difference we attribute to a pervasive diagenetic overprint in Hole 1221C. However, the visually good preservation of foraminifers in Hole 1220B and the consistency of the benthic foraminifer isotope results for species of both N. truempyi and Cibicidoides spp. suggest that these data record seafloor chemistry through the P/E boundary interval. Furthermore, the overall similarity of our benthic foraminiferal isotopic results for Hole 1220B and those of previously published records suggest that the new Pacific record captures at least part of the core of the P/E carbon isotope excursion. The PETM is only recorded in benthic foraminifers from Hole 1220B, an indication that δ18O from Hole 1221C may be overprinted by a secondary signal.

ACKNOWLEDGMENTS This research used samples and/or data provided by the Ocean Drilling Program (ODP). ODP is sponsored by the U.S. National Science Foundation (NSF) and participating countries under management of Joint Oceanographic Institutions (JOI), Inc. Funding for this research was provided by a Leg 199 postcruise grant from JOI/U.S. Science Support Program and NSF OCE02-44264.

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REFERENCES Katz, M.E., Katz, D.R., Wright, J.D., Miller, K.G., Pak, D.K., Shackleton, N.J., and Thomas, E., 2003. Early Cenozoic benthic foraminiferal isotopes: species reliability and interspecies correction factors. Paleoceanography, 18(2):10.1029/2002PA000798. Katz, M.E., Pak, D.K., Dickens, G.R., and Miller, K.G., 1999. The source and fate of massive carbon input during the latest Paleocene thermal maximum. Science, 286:1531–1533. Kennett, J.P., and Stott, L.D., 1991. Abrupt deep-sea warming, paleoceanographic changes and benthic extinctions at the end of the Palaeocene. Nature (London, U. K.), 353:225–229. Lu, G.Y., Adatte, T., Keller, G., and Ortiz, N., 1998. Abrupt climatic, oceanographic and ecologic changes near the Paleocene–Eocene transition in the deep Tethys basin: the Alademilla section, southern Spain. Eclogae Geol. Helv., 91:293–306. Lu, G.Y., and Keller, G., 1993. The Paleocene–Eocene transition in the Antarctic Indian Ocean: inference from planktic foraminifera. Mar. Micropaleontol., 21(1– 3):101–142. Lyle, M., Wilson, P.A., Janecek, T.R., et al., 2002. Proc. ODP, Init. Repts., 199 [Online]. Available from World Wide Web: . [Cited 2004-03-30] Röhl, U., Bralower, T.J., Norris, R.D., and Wefer, G., 2000. New chronology for the Late Paleocene Thermal Maximum and its environmental implications. Geology, 28:927–930. Thomas, E., and Shackleton, N., 1996. The Palaeocene–Eocene benthic foraminiferal extinction and stable isotope anomalies. In Knox, R.W.O’B., Corfield, R.M., and Dunay, R.E. (Eds.), Correlation of the Early Paleogene in Northwest Europe. Geol. Soc. Spec. Publ., 101:401–441.

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Figure F1. Hole 1220B carbon and oxygen isotope records from benthic foraminifers. Arrows indicate datum points selected for developing a timescale. δ18O (‰)

δ13C (‰) -1.5 197.50

-0.5

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Figure F2. Hole 1221C carbon and oxygen isotope records from benthic foraminifers. Arrows indicate datum points selected for developing a timescale. δ13C (‰) 0.0 152.00

0.5

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δ18O (‰) 2.0

2.5 -2.0

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Nuttalides truempyi Cibicidoides spp. Bulk CaCO3 152.50

Depth (mbsf)

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Figure F3. Carbon and oxygen isotope from Sites 1220 and 1221 plotted on a common timescale. Nutt = data from benthic foraminifer Nuttalides truempyi, cib = data from benthic foraminifer Cibicidoides spp. δ13C (‰) -1.5 54.5

-1.0

54.6 1220-nutt 1220-cib 1221-nutt 1221-cib

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Age (Ma)

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F. NUNES AND R.D. NORRIS DATA REPORT: HIGH-RESOLUTION STABLE ISOTOPE RECORDS

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Table T1. Stable isotope data from benthic foraminifers, Sites 1220 and 1221. (Continued on next page.) Nuttalides truempyi (‰)

Cibicidoides spp. (‰)

Core, section, interval (cm)

Depth (mbsf)

Age (Ma)

δ13C

δ18O

δ13C

δ18O

199-1220B20X-1, 15–17 20X-1, 20–22 20X-1, 25–27 20X-1, 30–32 20X-1, 35–37 20X-1, 40–42 20X-1, 45–47 20X-1, 50–52 20X-1, 55–57 20X-1, 60–62 20X-1, 65–67 20X-1, 70–72 20X-1, 75–77 20X-1, 80–82 20X-1, 85–87 20X-1, 90–92 20X-1, 95–97 20X-1, 100–102 20X-1, 105–107 20X-1, 110–112 20X-1, 115–117 20X-1, 120–122 20X-1, 125–127 20X-1, 130–132 20X-1, 135–137 20X-1, 140–142 20X-1, 145–147 20X-1, 146–148 20X-2, 0–1 20X-2, 5–7 20X-2, 10–12 20X-2, 15–17 20X-2, 20–22 20X-2, 25–27 20X-2, 30–32 20X-2, 35–37 20X-2, 40–42 20X-2, 45–47 20X-2, 50–52 20X-2, 55–52 20X-2, 60–62 20X-2, 65–67 20X-2, 70–72 20X-2, 75–77 20X-2, 80–82 20X-2, 85–87 20X-2, 90–92 20X-2, 95–97 20X-CC, 0–2 20X-CC, 8–10

197.55 197.60 197.65 197.70 197.75 197.80 197.85 197.90 197.95 198.00 198.05 198.10 198.15 198.20 198.25 198.30 198.35 198.40 198.45 198.50 198.55 198.60 198.65 198.70 198.75 198.80 198.85 198.86 198.90 198.95 199.00 199.05 199.10 199.15 199.20 199.25 199.30 199.35 199.40 199.45 199.50 199.55 199.60 199.65 199.70 199.75 199.80 199.85 199.85 199.93

54.5000 54.5200 54.5401 54.5601 54.5802 54.6002 54.6203 54.6403 54.6603 54.6804 54.7004 54.7205 54.7405 54.7606 54.7806 54.8007 54.8207 54.8407 54.8608 54.8808 54.9009 54.9209 54.9410 54.9610 54.9811 55.0011 55.0211 55.0252 55.0412 55.0612 55.0813 55.1013 55.1214 55.1414 55.1615 55.1815 55.1863 55.1910 55.1958 55.2006 55.2054 55.2101 55.2149 55.2197 55.2245 55.2292 55.2340 55.2388 55.2388 55.2464

0.67 0.71

–0.42 –0.46

0.57 0.62 0.64 0.57 0.73 0.69 0.77 0.72 0.70 0.76 0.66 0.68 0.60 0.64 0.71 0.71 0.70 0.75 0.65 0.71 0.68 0.56 0.62 0.45 0.50

–0.50 –0.58 –0.49 –0.62 –0.48 –0.50 –0.49 –0.52 –0.53 –0.39 –0.45 –0.45 –0.58 –0.48 –0.42 –0.40 –0.47 –0.25 –0.48 –0.30 –0.28 –0.31 –0.33 –0.31 –0.40

0.50 0.32 0.41 0.15 0.32 0.21 0.26 0.21 0.26 0.45 0.39 0.32 0.52 0.40 0.22 0.49 0.39 0.22 -0.05 0.00 0.15 0.58 0.51 0.58 0.37 0.34 0.34 0.51

–0.23 –0.23 –0.28 –0.42 –0.06 –0.29 –0.26 –0.29 –0.18 –0.28 –0.15 –0.30 –0.22 –0.24 –0.17 –0.32 –0.25 –0.19 –0.16 –0.13 –0.07 –0.39 –0.31 –0.24 –0.36 –0.30 –0.26 –0.28

0.37 0.12 -0.27 0.24 -0.65 -0.58 -0.70 -0.57 -1.42

–0.35 –0.60 –0.66 –0.59 –0.99 –1.02 –1.03 –0.98 –1.04

0.33 -0.14 -0.25 -0.34 -0.46 -0.64 -0.84 -0.71 -0.08 -0.58

–0.30 –0.51 –0.54 –0.60 –0.73 –0.94 –1.12 –0.91 –0.92 –0.88

0.64 0.51 0.79

–0.38 –0.34 –0.32

0.64 0.56 1.16

–0.26 –0.28 –0.31

0.62 0.81

–0.28 –0.19

0.82 0.55

–0.19 –0.01

199-1221C11X-2, 3–5 11X-2, 23–25 11X-2, 33–35 11X-2, 43–45 11X-2, 53–55 11X-2, 62–64 11X-2, 73–75 11X-2, 83–85 11X-2, 93–95 11X-2, 103–105 11X-2, 113–115 11X-2, 124–126 11X-2, 133–135 11X-2, 144–146 11X-3, 0–3

151.93 152.13 152.23 152.33 152.43 152.52 152.63 152.72 152.83 152.93 153.03 153.14 153.23 153.34 153.40

54.4911 54.5605 54.5952 54.6299 54.6646 54.6958 54.7340 54.7652 54.8034 54.8380 54.8727 54.9109 54.9421 54.9803 55.0011

0.81 0.83

–0.14 –0.05

0.71 0.53 0.71 0.89 0.79 0.78 0.98 0.87 0.78 0.75 0.78

–0.19 –0.30 –0.29 –0.24 –0.37 –0.38 –0.28 –0.27 –0.39 –0.30 –0.19

0.81 0.79 0.72 0.69 0.43 0.52 0.87 0.60 0.57 0.22

–0.11 0.16 0.03 –0.11 –0.06 –0.07 –0.25 –0.18 –0.28 –0.08

0.70 0.64 0.67

–0.29 –0.32 –0.21

Bulk CaCO3 (‰) δ13C

δ18O

1.46 1.44 1.47 1.33 1.53 1.30 1.40 1.44 1.46 1.51 1.32 1.38 1.47 1.50 1.45 1.44 1.56 1.43 1.42

–1.43 –1.43 –1.34 –1.36 –1.36 –1.43 –1.55 –1.44 –1.43 –1.40 –1.57 –1.31 –1.35 –1.34 –1.14 –1.30 –1.15 –1.22 –0.94

1.43

–1.20

1.26 1.21 1.13 1.07 0.66 0.70 0.64 0.62 0.54 0.48 1.93 2.03 1.98 1.36 1.61 1.58 1.03 1.09 1.14 1.27

–0.60 –0.65 –0.54 –0.34 –0.06 0.29 0.22 0.70 0.59 –0.30 3.45 4.02 3.67 3.35 3.48 2.99 –0.06 0.00 –0.04 0.03

1.50

–1.52

F. NUNES AND R.D. NORRIS DATA REPORT: HIGH-RESOLUTION STABLE ISOTOPE RECORDS

12

Table T1 (continued). Nuttalides truempyi (‰)

Cibicidoides spp. (‰)

Bulk CaCO3 (‰)

Core, section, interval (cm)

Depth (mbsf)

Age (Ma)

δ13C

δ18O

δ13C

δ18O

δ13C

δ18O

11X-3, 4–6 11X-3, 5–8 11X-3, 9–12 11X-3, 10–13 11X-3, 10–12 11X-3, 15–18 11X-3, 15–17 11X-3, 16–19 11X-3, 20–22 11X-3, 24–26 11X-3, 25–28 11X-3, 30–33 11X-3, 34–36 11X-3, 35–38 11X-3, 40–42 11X-3, 44–46 11X-3, 45–48 11X-3, 50–52 11X-3, 52–54 11X-3, 54–56 11X-3, 56–58 11X-3, 58–60 11X-3, 60–62 11X-3, 62–64 11X-3, 70–72 11X-3, 88–90 11X-3, 90–92 11X-3, 92–94 11X-3, 94–96 11X-3, 90–92 11X-3, 96–98 11X-3, 98–100 11X-3, 100–102 11X-3, 105–108 11X-3, 110–113 11X-3, 115–118 11X-3, 120–123 11X-3, 125–128 11X-3, 130–133 11X-3, 135–138 11X-3, 140–142

153.44 153.45 153.49 153.50 153.50 153.55 153.55 153.56 153.60 153.64 153.65 153.70 153.74 153.75 153.80 153.84 153.85 153.90 153.92 153.94 153.96 153.98 154.00 154.02 154.10 154.28 154.30 154.32 154.34 154.35 154.36 154.38 154.40 154.45 154.50 154.55 154.60 154.65 154.70 154.75 154.80

55.0150 55.0184 55.0323 55.0358 55.0358 55.0531 55.0531 55.0566 55.0705 55.0844 55.0878 55.1052 55.1191 55.1225 55.1399 55.1537 55.1572 55.1746 55.1815 55.1843 55.1870 55.1898 55.1926 55.1953 55.2064 55.2312 55.2340 55.2368 55.2395 55.2409 55.2423 55.2451 55.2478 55.2547 55.2616 55.2685 55.2754 55.2824 55.2893 55.2962 55.3031

0.86 1.31 1.18 0.76

–0.08 0.07 0.08 0.26

0.80 1.00 0.74

0.11 0.16 0.16

1.59

–1.69

0.68 0.67 1.42

0.24 –0.24 0.12

0.56 0.75 0.99

0.16 –0.22 0.24

1.59 1.54 1.51 1.45

–1.46 –1.52 –1.35 –1.18

1.40

–1.69

0.62 0.69 0.74 0.61 0.60

–0.36 0.19 0.20 –0.20 0.18

0.33 0.51 0.49 0.54 0.41

–0.36 0.24 0.22 –0.23 0.17

1.35 1.28

–1.43 –1.55

1.22 1.22

–1.49 –1.41

0.44 0.28

–0.33 0.32

–1.54 –1.80

0.40 0.52 0.72 0.88 0.50 0.48 0.11 0.06 0.03 0.15 0.13

–0.33 0.28 0.37 0.36 0.52 0.51 0.45 0.65

1.10 1.04

0.07 0.18 0.30 0.47 0.14 0.24 0.58 1.06 1.05 1.00 0.98

0.31 0.27 0.01 0.10 0.25 0.17 0.16 0.26

1.06

–1.73

0.04

0.12

1.08

–1.83

0.84 0.74 0.81

0.26 0.07 –0.06

1.94

–1.07

1.75

–1.14

0.98 0.89

0.04 0.02

0.91 0.89

0.19 0.11

1.07

0.09

1.19 1.20 1.27 1.20 1.28 1.12

0.02 0.06 0.03 0.01 0.04 0.01

0.88 0.94 1.03 0.83 0.91 1.03 0.70 0.35

0.17 0.03 0.10 0.06 0.12 0.06 0.18 0.12

1.54 1.63 2.24 2.20 2.11 2.32 2.15 2.27 2.27

–1.64 –1.37 –1.09 –1.17 –1.07 –1.35 –0.97 –1.23 –1.17